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Water quality of the upper Orange River
No full textEnglish: The Upper Orange River is defined as the region between the source in the Drakensberg (Lesotho)
and the Orange-Vaal confluence. Information on the water quality, phytoplankton composition
and the influence of the dams on the Upper Orange River is limited. This study was conducted in
order to determine seasonal and spatial patterns in the river system., as well as to determine the
influence of the tributaries and the two major dams on the river system. Physical, chemical and
biological factors were taken into account.
Hypolimnetic water released from the Gariep and Vanderkloof Dams caused a significant decrease
in the temperature downstream of the dams. The dams acted as sediment traps and caused the TSS
and turbidity in the river system to decrease. A decrease in turbidity resulted in an increase in the
light penetration. This created more favourable conditions for primary production and led to algal
blooms in the dams.
The dams are used for hydro-electric power generation and almost completely diminished seasonal
flow patterns. This changed the Upper Orange River into a highly regulated system. The
interference with seasonal flow patterns in the river is probably one of the main reasons for
outbreaks of the pest blackfly, Simulium chutteri downstream of the dams.
The oxygen-depth profile in the Gariep Dam during summer stratification indicated relatively high
dissolved oxygen concentrations in the epilimnion (8.2 mg.l-1) and anoxic, near anaerobic,
conditions (0.1 mg.l-1) in the hypolimnion. The oxygen decline in the hypolimnion was indirectly
the cause of high algal production in the epilimnion during algal blooms.
The average pH of the Upper Orange River system was mainly alkaline at 8.1, with an average
total alkalinity of 95.2 mg CaC03.rl. This suggested that the Upper Orange River is a wellbuffered
system.
The average conductivity in the Upper Orange River was relatively low at 19.6 mS.m-1, but
increased significantly since 1980. Major ions at Aliwal North occurred in the following
proportions, i.e. Ca> Na > Mg > K for cations and CO3 > Cl> SO4 for anions. In the Gariep Dam and at Marksdrift the proportions were: Na > Ca > Mg > K for cations and CO3 > Cl > SO4 for
anions.
The average P04-P concentration was relatively low at 28.3 µg.l-1 and the average TP
concentration was 107 µg.I-1. The average N03-N concentration was high at 312 µg.l-1 and
increased in the dams and downstream probably due to agricultural fertilizers and nitrogen fixation
by algae.
The average chlorophyll a concentration ranged between 0.4 and 1084 µg.I-1, with and average
concentration of 10.8 µg.l-1. The very high chlorophyll a concentration was due to a bloom of
Microcystis sp. during February in the Gariep Dam. Phytoplankton dynamics manifested
themselves in seasonal cycles. Cyanobacteria and Bacillariophyceae dominated during warmer
months. The Chlorophyceae replaced cyanobacteria during cooler months.
Light penetration in the Gariep Dam and the Vaal River had a major effect on the primary
production. The maximum primary production in the Gariep Dam was 14.6 mg C. mg Chla-1 h-1
and in the Vaal River the maximum primary production was 76 mg C. mg Chla-l. h-1. According
to the primary production in the Gariep Dam it can be classified as mesotrophic, while the high
primary production in the Vaal River indicated eutrophic conditions.
The dams exert major influences on the physical, chemical and biological parameters in the river.
Low SASS4 scores were obtained and are an indication of poor water quality. This could be
ascribed to disturbances by the dams. The serial discontinuity concept (SDC) is applicable in the
Upper Orange River. It is likely that agricultural runoff, as well as urban and industrial pollution
from the Vaal River catchment would mask the downstream recovery after the Orange- Vaal
confluence.Afrikaans: Die Bo-Oranjerivier kan gedefinieer word as die gebied tussen die oorsprong in the Drakensberge (Lesotho) en die Oranje-Vaal samevloei. Beperkte inligting is beskikbaar oor die waterkwaliteit en die invloed van die damme op die Bo-Oranjerivier. Die doel van die studie was om seisoenale and ruimtelike veranderinge in die rivierstelstel te bepaal, sowel as om te kyk na die invloed van die sytakke en die twee groot damme op die rivierstelstel. Fisiese, chemiese en biologiese faktore is ondersoek.
Water wat vrygestel is vanuit die hipolimnion in die Gariep en Vanderkloof damme het gelei tot betekenisvolle verlaging in die watertemperatuur in die rivierstelsel onder die damme. Die damme het sediment teruggehou en dit het gelei tot verlaagde totale gesuspendeerde materiaal (TSS) en dus ook verlaagde troebelheid. Verlaagde troebelheid het verbeterde ligindringing tot gevolg gehad, wat gunstige toestande geskep het vir algopbloeie.
Die damme, wat gebruik word vir hidro-elektriese kragopwekking, het seisoenale vloeipatrone feitlik heeltemal uitgewis en dus die Bo-Oranjerivier verander in 'n hoogs gereguleerde stelsel. Die verandering in seisoenale vloei patrone is moontlik een van die hoof oorsake van die probleme wat onder die damme ondervind word met die swartvliegie, Simulium chutteri.
Die suurstof-diepte profiel in die Gariep dam gedurende somer stratifikasie het relatief hoë konsentrasies opgeloste suurstof getoon in die epilimnion (8.2 mg.l-1) en feitlik anoksiese toestande in die hipolimnion (0.1 mg.I-1). Die lae suurstof konsentrasies in die hipolimnion was die indirekte gevolg van die hoë alg produksie in die epilimnion gedurende 'n opbloei.
Die gemiddelde pH (8.1) was hoofsaaklik alkalies, met 'n gemiddelde totale alkaliniteit van 95.2 mg CaC03.l-1 . Dit dui daarop dat die Bo-Oranjerivier stelstel goed gebuffer is.
Die geleiding in die Bo-Oranjerivier was relatief laag met 'n gemiddeld van 19.6 mS.m-1. Die samestelling van makro ione by Aliwal Noord was soos volg: . Ca > Na > Mg > K vir katione en CO3 > Cl > SO4 vir anione. Die samestelling in die Gariep dam en by Marksdrift was soos volg: Na> Ca > Mg > K vir katione en CO3 > Cl > SO4 vir anione.
Die gemiddelde konsentrasie PO4-P was relatief laag teen 28.3 µg.l-1 en die gemiddelde konsentrasie TP was 107 µg.l-1. The gemiddelde konsentrasie N03-N was hoog teen 312 µg.l-1 en het vermeerder stroom-af moontlik a.g.v. bemestingstowwe en stikstof-vaslegging deur alge.
Die chlorofil α konsentrasie het gewissel tussen 0.4 en 1 084 µg.l-1 met gemiddeld 10.8 µg.l-1. Die hoë konsentratsie was as gevolg van 'n Microcystis opbloei in die Gariep dam gedurende Februarie. Fitoplankton dinamika het seisoenale patrone gevolg. Cyanobakterieë en Bacillariophyceae het gedomineer gedurende die warmer maande en Chlorophyceae het cyanobakterieë vervang gedurende die koeler maande.
Primêre produksie in die Gariep dam en in die Vaalrivier is hoofsaaklik bepaal deur ligindringing. Maksimum produktiwiteit in die Gariep dam was 14.6 mg C. mg Chla-1 . h-1 en in die Vaalrivier was dit 76 mg C. mg Chla-1 . h-1 . Na aanleiding van die primêre produksie kan die Gariep dam geklassifiseer word as mesotrofies, terwyl die hoë produksie in die Vaalrivier dui op eutrofiese toestande.
Die damme beïnvloed die fisiese, chemiese en biologiese toestande in die rivier. Lae SASS4 waardes is gevind, wat op swak waterkwaliteit dui. Die lae waardes kan toegeskryf word aan die versteuring van die rivierstelsel deur die damme. Die SDC (serial discontinuity concept) is van toepassing op die Bo-Oranjerivier. Dit is moontlik dat die herstel van die rivier stroomaf verskans kan word deur afloop vanaf landbou bemestingstowwe, sowel as deur stedelike en industriële besoedeling vanaf die Vaalrivier opvangsgebied, na die Oranje-Vaal samevloei
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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